In the buffer at the beginning of the system, several elements can be prepared at the same time © Hasslacher Norica Timber
In spring, Hasslacher Norica Timber put its new surface refinement centre for CLT into operation. The fine grinding and coating machines consist of numerous cleverly designed elements. In the fine grinding machine, several aggregates rotate without a specific direction in order to create visible and excellent laminations with an evenly fine surface. This best prepares the surface for the coating process. The system is very flexible when it comes to production. Depending on the customer’s requests and needs, brushed and structured surfaces can be produced as well.
After grinding, the CLT elements, which are machined according to the customer’s requests, are refined in the coating machine. This machine is equipped with computer-operated overhead conveyors with single beams thanks to which it can hold several panels with an overall length of up to 20 metres. In order to identify the panels’ geometry, scanners are used which then determine the spraying programme for every single panel. The panels’ inclination is also measured so as to guarantee the optimal spraying distance on every spot of the up to 3.2 metre high elements. The buffer at the beginning of the system has six beams on which elements can be hung. Every spraying robot is equipped with four fine-spraying nozzles and “on-the-fly” paint changers. The coating is done in a closed booth with a controlled flow of fresh and exhaust air. The robots are able to access several different paints through automatic change.
The two robotic arms coat CLT elements of up to 20 metres in length and 3.2 metres in width © Hasslacher Norica Timber
The buffer at the end of the system also has six beams and serves as a warm air dryer which includes air dehumidification. The intermediate grinding machine is located in the return conveyor and allows for an optimal preparation for a possible second coating process. The entire system is suitable for elements of up to 20 metres in length and 3.2 metres in width. For coating, only water-based materials are used, and clients can choose numerous colours and hues as well as additional layers which protect the wood from yellowing or blue stain. For big construction sites, for example, Hasslacher Group recommends a protective layer for end grain wood.
There are no limitations to the application of materials: They can be applied on every side and on the edges and in an automatic change.
“Projects like HoHo would be unthinkable”
According to Andreas Weichsler, factory manager of the production site in Stall im Mölltal, Hasslacher Group is able to produce CLT surfaces which resemble furniture surfaces thanks to this equipment. The surface refinement of cross-laminated timber is necessary: “Without our new system, projects like the 24-storey Hoho in Vienna, for which we deliver wall elements with a refined surface and a two-layer coating, would be unthinkable”, sums up Weichsler with regard to the advantages of the surface refinement centre.
